In 1973, applicant Carl Parise invented a hot water vacuum extraction machine which was capable of functioning in the home to wet clean wall to wall carpeting and the like, and which could be readily handled by a housewife in contrast to "steam cleaners" generally employed by commercial operators. Such machines operate by jetting hot water (or water and cleaner solution) onto the rug, at a point adjacent to a vacuum pick-up head, the vacuum head acting to remove the water and entrained dirt from the rug near the point of water spray application. Dirty water is normally returned, in commercial operations, either to a relatively large cleaner unit within the room bearing the carpet being cleaned or through extended hoses, to a truck mounted apparatus exterior of the building housing the carpeting.
The smaller, lightweight Parise machines for the housewife were an instant success, and such machines were provided for lease purposes to grocery stores, hardware stores, convenience stores and the like.
A number of patents have issued to applicant Carl Parise with respect to hot water vacuum extraction machines. Representative U.S. Pat. Nos. are:
3,896,521 "HOME CLEANING SYSTEM" PA1 3,911,524 "STEAM CLEANER DUMP BUCKET" PA1 4,015,589 "STEAM CLEANER PROTECTION SCREEN" PA1 4,046,989 "HEATER FOR A HOT WATER EXTRACTION UNIT" PA1 4,075,733 "CLEANING HEAD" PA1 4,078,908 "HYDRO AIR FILTER" PA1 4,083,705 "REVERSE FLOW HYDRO AIR FILTER FOR WET/DRY PICK UP SYSTEM" PA1 4,088,462 "HOT WATER EXTRACTION UNIT" PA1 4,122,579 "STEAM CLEANER DUMP BUCKET"
Such "home use" hot water vacuum extraction machines require electrically powered vacuum and water pumps within the casing proper of the machine and remote from the vacuum pick-up head itself, which is normally coupled to the machine via a rigid tubular wand and flexible hose to return the water and entrained dirt to a removable dump tank carried by the machine casing. In some circumstances, it is desirable to employ a power scrubber head bearing a motor which rotates a revolvable brush or the like and adjacent the vacuum extraction nozzle slot. There exists the possibility of electrical short and the possibility of electrical shock to the machine operator from such electrical elements. Carl Parise, within several years of developing his "home use" hot water vacuum extraction machines, realized the necessity to electrically insulate the electrical elements within the vacuum extraction machines from areas of possible contact by the operator such as the return water dump tank.
A double insulated water pump was devised by the applicant and incorporated within the commercial hot water vacuum extraction machines some years ago, utilizing a technique wherein the shaft which extends from the water pump drive motor to the impeller and through a sealed bushing, was electrically insulated by an insulation material sheath, to prevent the conducting of electricity through the shaft itself to the impeller and thence to the water leading to the spray head. Further, due to the efforts of applicant, within the past several years, a commercialy available double insulated vacuum pump was produced by Lamb Electric, a Division of AMETEK Corporation which is also electrically double insuating. It utilizes, in the same manner, an electrical insulation sheath about the shaft extending from the vacuum pump motor to the vacuum pump impeller, functioning to provide the suction necessary to the vacuum head for vacuum extraction of the water and entrained dirt adjacent the area of liquid spray onto the carpet.
For the past several years, the corporate assignee of this application has employed plastic as the material forming the exterior casing of its hot water vacuum extraction machines. Initially, such machines included a hot water storage tank and a separate dirty water dump tank formed of metal and mounted within the electrically insulation material plastic casings. Gradually, such metal components have been replaced by plastic components to further prevent electrical shock to the operator by possible electrical short circuit through the water itself from one of the components such as the water pump.
It is, therefore, a primary object of the present invention to provide an improved double insulated hot water vacuum extraction machine in which the major components including the casing, the hot water storage tank and the dump tank, are all formed of electrical insulative material, and wherein an open top double wall plastic hot water storage tank mounts within an injected plastic casing, is spaced from the walls of the casing itself to thermally insulate the hot water tank, and wherein a plastic removable cylindrical dump tank closely fits the interior of the cylindrical inner wall of the storage tank to form a compact assembly.
It is a further object of the present invention to provide an improved double insulated vacuum extraction machine which may be selectively employed as a dry vacuum cleaner or a wet vacuum extraction machine at the convenience of the operator and in an extremely simple and effective manner.